lookup> .hdf

.HDF·File Extension

HDF Data & Text — A .hdf file is a HDF Data & Text. It is a text-based data format widely used for configuration files, data interchange and API payloads.

Data & Textapplication/x-hdf

Quick facts

Extension.hdf

File typeHDF Data & Text

MIME typeapplication/x-hdf

CategoryData & Text

Charset—

Compressible—

What is .hdf

What is a .hdf file?

A .hdf file is a HDF Data & Text. It is a text-based data format widely used for configuration files, data interchange and API payloads.

In the mime-db registry it maps to application/x-hdf. When serving .hdf over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to application/x-hdf — and is delivered over HTTP via the Content-Type header.

How to open .hdf files

Use VS Code or Notepad++ to open and edit .hdf files.
Any text editor (Notepad, VS Code) can inspect the raw content as text.

Developer info

When served over HTTP, responses should set the following header:

Content-Type: application/x-hdf

Common software that reads/writes .hdf:

VS CodeNotepad++Sublime Textjq

Relation chain

.hdfextension of

format

HDF Data & Textserved as

mime type

application/x-hdfsent via header

http header

Related extensions

Related MIME types

Common uses

Configuration files
Data interchange between systems
API request and response payloads
Logs and data exports

How to edit .hdf files

Open the file with VS Code, make your changes and save.
Most editors preserve the original formatting and encoding — avoid changing the charset.

How to create .hdf files

Create a new file and save it with the .hdf extension, or export this format from VS Code.

Frequently asked questions

What programs can open .hdf files?

Common options include VS Code, Notepad++, Sublime Text. You can also open many of these files with built-in viewers or a browser.

How do I create a .hdf file?

Create a new file in any text editor or the app that owns the format and save it with the .hdf extension.

What is the relationship between .hdf and the application/x-hdf MIME type?

application/x-hdf is the media type identifier used for .hdf files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-09-13

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